“A 250gr bullet in .338 does not have sufficient sectional density to stay true over that distance.
A 300gr boat tail would do the trick. The BC must be at least .6”
They shouldn’t have been shooting a Sierra bullet at all. First of all, the Lapua 250-gr lockbase bullet is the gold standard in that weight class (the same bullet Cpl Harrison used for his 2707-yard shots [plural] in Afghanistan) because it isn’t unsettled by the transonic transition. Harrison’s bullet was down to ~800 fps at impact, so transonic stability was crucial.
Second, Berger Bullets’ chief ballistician, Bryan Litz, is blazing new trails in bullet design and long-range precision shooting. Civilian hobbyist shooters all over the fruited plain are scoring hits at incredible ranges with Litz-designed Berger Bullets. Many of them use 1500 yards for a warm-up. His .338 big hitter is a 300-grain hybrid design (ogive is part tangent, part secant) with a (claimed) G1 BC of 0.822.
To: Yo-Yo
“I highly doubt that a suppressor gives any bullet more velocity.
What I would believe is that a suppressor retains much of the muzzle blast as the bullet exits, so the bullet is less disturbed as it leaves the muzzle.”
It does add a small bit, a few fps. It’s called “freebore boost.” And you’re right, the bullet exiting the muzzle is less disturbed/more accurate to boot.
A 250gr .338 bullet is just not long enough to maintain stability of those distances. As you said, once it drops below the sound barrier in velocity, it wobbles off course.
Here’s a new one at .72.
It would be my choice for distance in any .338 or .340 mag.